I have had a lump on the back of my head for about 3 days, its is about 1 cm away from my right ear and about 2 cm up from hairline, it is about the size of a large pea. Noticec it around 3 days ago when i was brushing my hair as it is very painful to touch. DH has had a look and its not red or a spot, you cant see anything to look under hair but can feel the lump. How long would you leave before gp? I am hoping it is just a gland